TW202226794A - Time-division multiplexing scheduler and device - Google Patents

Abstract

Disclosed is a time-division multiplexing (TDM) scheduler capable of determining a service order for serving N packet transmission demanders. The TDM scheduler includes: N current count value generators configured to serve the N packet transmission demanders respectively, and generate N current count values according to parameters of the N packet transmission demanders, a latest scheduling result generated by the EDD scheduler previously, and a predetermined counting rule; and an earliest due date (EDD) scheduler configured to generate a current scheduling result for determining the service order according to the N current count values and a predetermined urgency decision rule, wherein an extremum of the N current count values relates to one of the N packet transmission demanders, and the EDD scheduler selects this demander as the one to be served preferentially.

Description

Time-sharing multiplexing scheduler and device

The present invention relates to a scheduler and a scheduling device, and more particularly, to a time-sharing multiplexing scheduler and a time-sharing multiplexing scheduling device.

A typical switch (eg, an Ethernet switch) uses time-division multiplexing (TDM) technology to process packet transmissions across multiple ports; more specifically, the switch operates on a time slot ( The packet transmission of one transmission port is processed in a time slot, and the packet transmission of the transmission ports is processed according to a predetermined sequence in a plurality of consecutive time slots. When the total I/O bandwidth of the transmission ports is greater than the core bandwidth of the switch, the switch cannot fully meet the bandwidth requirements of all transmission ports. In this case It is called oversubscription (OS); at this time, the switch will fully meet the bandwidth requirements of the transmission ports in the full line rate mode based on the attributes of the transmission ports, and meet the bandwidth requirements of the transmission ports in the oversubscription mode. part of the bandwidth requirements of the port.

As mentioned above, a general network switch manually plans multiple TDM tables, including full line-rate TDM tables and oversubscribed TDM tables, to define the aforementioned predetermined order, thereby allocating time slots to multiple transmission ports for packet transmission. . However, the above method is labor-intensive, different TDM tables need to be planned according to the number of different transmission ports, and it is difficult to fairly allocate the bandwidth to the transmission ports in the over-subscription mode.

One of the objectives of the present disclosure is to provide a time-division multiplexing (TDM) scheduler and apparatus to avoid the problems of the prior art.

An embodiment of the TDM scheduler of the present disclosure can determine a service order of N packet transmission requesters, where N is an integer greater than one. This embodiment includes N current count value generators and an earliest due date (EDD) scheduler. The N current count value generators are respectively used for serving the N packet transmission request groups. The N current count value generators generate N current count values according to the parameters of the N packet transmission request groups, a recent scheduling result and a predetermined counting rule. The earliest expiration scheduler is used for generating a current scheduling result according to the N current count values and a predetermined urgency judgment rule, wherein the current scheduling result determines the service order, and the latest scheduling result is the earliest scheduling result previously generated by the scheduler.

Another embodiment of the TDM scheduler of the present disclosure can determine a service order of N packet transmission requesters, wherein the N packet transmission requesters include a first requester and a second requester. This embodiment includes N current count value generators and an earliest expiration scheduler. The N current count value generators are respectively used to serve the N packet transmission requesters; each current count value generator is used to generate a count value; the N current count value generators generate N current count values in total. The N current count value generators include a first count value generation circuit and a second count value generation circuit for serving the first demander and a second demander, respectively. The first (second) count value generating circuit includes: a first (second) storage circuit for storing the first (second) parameter configuration of the first (second) demander; and a first (second) The second) counting circuit is used to update a first (second) previous count value according to a plurality of first (second) input parameters and a preset counting rule, so as to generate a first (second) count value of the N current count values. second) current count value, wherein the plurality of first (second) input parameters include the first (second) parameter configuration and the first (second) previous count value derived from A recent scheduling result previously generated by the EDD scheduler, the first (second) previous count value and the first (second) current count value both fall within a first (second) count range, the The first (second) count range is determined by the first (second) parameter configuration and includes a first (second) extreme value. The EDD scheduler is used for generating a current scheduling result according to the N current count values and a predetermined urgency judgment rule for determining the service order; for example, an extreme value among the N current count values is associated with One of the N packet transmission demanders, the EDD scheduler selects the demander associated with the extreme value as a top priority object according to the preset urgency judgment rule.

An embodiment of the TDM scheduler of the present disclosure includes a TDM scheduler and a port scheduler. The TDM scheduler includes N current count value generators and an EDD scheduler. The N current count value generators are respectively used to serve N packet transmission demand groups; the N current count value generators are based on the parameters of the N packet transmission demand groups, a most recent one previously generated by the EDD scheduler The scheduling result and a predetermined counting rule generate N current count values. The EDD scheduler is used for generating a current scheduling result according to the N current count values and a predetermined urgency judgment rule. The transmission port scheduler includes N scheduling circuits and a multiplexer. The N scheduling circuits are respectively used for serving the N packet transmission request groups; each of the N packet transmission request groups includes at least one transmission port, and each scheduling circuit is used for selecting according to a predetermined algorithm A transmission port of the packet transmission request group served by the scheduling circuit, therefore, the N scheduling circuits select N transmission ports in total. The multiplexer is used for outputting a transmission port selection signal according to a top priority object indicated by the current scheduling result to indicate one of the N transmission ports as a selected transmission port, so as to allow the selected transmission port to transmit ; the highest priority object is one of the N packet transmission request groups; the selected transmission port is one of the M transmission ports of the highest priority object, where M is a positive integer.

With regard to the features, implementations and effects of the present invention, preferred embodiments are described in detail as follows in conjunction with the drawings.

The time-division multiplexing scheduler (TDM scheduler) and device of the present disclosure can automatically allocate time slots to a plurality of packet transmission requesters, which not only saves manpower significantly, but also quickly realizes time slot allocation. planning. The TDM scheduler and device can be used in a network device (eg, an Ethernet switch), but its application is not limited thereto.

FIG. 1 shows an embodiment of the TDM scheduler of the present disclosure. The TDM scheduler 100 of FIG. 1 can determine the number of N packet transmission requesters MG1 ˜MGn (eg, N media access control groups (MAC groups), each MAC group includes at least one transmission port). A service order, where N is an integer greater than one. The TDM scheduler 100 includes N current count value generators 110 - 1 to 110 - n and an earliest due date (EDD) scheduler 120 .

；因此，N個當前計數值產生器110-1~110-n產生N個當前計數值

。每個當前計數值產生器

的一實施例包含一儲存電路

（例如：暫存器）與一計數電路

如圖2所示。儲存電路112-k用來儲存封包傳輸需求者MGk的參數配置。計數電路114-k用來依據封包傳輸需求者MGk的複數個輸入參數（例如：封包傳輸需求者MGk的參數配置以及一最近排程結果如後所述）與一預設計數規則，更新封包傳輸需求者MGk的一先前計數值，以產生封包傳輸需求者MGk的當前計數值MGk_DCNT_VAL，其中第k時槽的先前計數值是第(k-1)時槽的當前計數值。本領域具有通常知識者可依據本揭露，利用一已知計數器與一控制電路（未顯示於圖）來實現計數電路114-k，其中該控制電路用來開始與暫停該已知計數器的計數，並用來重置該計數器（或說載入該計數器的初始計數值）。 See Figure 1. The N current count value generators 110-1 to 110-n are respectively used to serve the N packet transmission requesters MG1 to MGn. Each of the N current count value generators 110-1 to 110-n is used to generate a current count value

; Therefore, N current count value generators 110-1 to 110-n generate N current count values

. each current count value generator

An embodiment of the includes a storage circuit

(Example: Scratchpad) and a counting circuit

as shown in picture 2. The storage circuit 112-k is used to store the parameter configuration of the packet transmission requester MGk. The counting circuit 114-k is used for updating the packet transmission according to a plurality of input parameters of the packet transmission demander MGk (for example, the parameter configuration of the packet transmission demander MGk and a latest scheduling result will be described later) and a preset counting rule A previous count value of the demander MGk to generate the current count value MGk_DCNT_VAL of the packet transmission demander MGk, wherein the previous count value of the kth time slot is the current count value of the (k-1)th time slot. Those skilled in the art can implement the counting circuit 114-k by using a known counter and a control circuit (not shown in the figure) according to the present disclosure, wherein the control circuit is used to start and pause the counting of the known counter, And used to reset the counter (or load the initial count value of the counter).

As mentioned above, an embodiment of the default counting rule includes a decrement/increment counting rule and an exception rule. When the plurality of input parameters do not meet the exception conditions defined by the exception rule, the counting circuit 114-k decreases/increases the previous count value by a preset value (eg, 1) to generate the current count value; and when When the plurality of input parameters satisfy the exception condition defined by the exception rule, the counting circuit 114-k may perform at least one of the following operations according to the type of the exception condition: when the packet transmission requester MGk is selected as the Kth time slot A highest priority object or when the transmission opportunity of the Kth time slot is given up due to no priority service requirement, the initial count value MGk_DCNT_INIT of the counting circuit 114-k (explained in the following paragraph) is loaded as its value at the (K+1)th time The current count value of the slot; the previous count value of the slot at the (K+1)th time of the counting circuit 114-k when the packet transmission requester MGk is not selected as the highest priority object at the Kth time (ie: the counting circuit When the current count value of the Kth slot of 114-k is the extreme value (for example: minimum or maximum value) within its counting range, the previous count value is output as the (K+1)th of the counting circuit 114-k ) the current count value of the time slot; when the packet transmission demander MGk is set in the oversubscription mode and the Kth time slot is selected as the highest priority object, if the current count value of the Kth time slot of its counting circuit 114-k The value is not the extreme value within the counting range of the counting circuit 114-k, the previous count value of the (K+1)th time slot of the counting circuit of each of the other packet transmission demanders set in the oversubscription mode is decreased/increased by one Compensation value (eg: the preset value plus a difference as described later) to generate the current count value of the (K+1)th time slot of the counting circuit. In this embodiment, a plurality of input parameters of the packet transmission demander MGk include its parameter configuration and its previous count value, and the parameter configuration includes the initial count value MGk_DCNT_INIT of the counting circuit 114-k; the packet transmission demander MGk's previous count value Both the numerical value and the current count value fall within a count range, which is determined by the parameter configuration and includes an extreme value (for example: the minimum or maximum value within the count range), and the other count within the count range. An extreme value (eg: the maximum or minimum value within the count range) can be used as the initial count value for the previous count value, and the count range (ie: the maximum value minus the minimum value within the count range) is proportional to the packet The bandwidth allocated to the transmission demander MGk.

As mentioned above, the previous count value of the packet transmission requester MGk is derived from a latest scheduling result; more specifically, the current scheduling result of the (K-1)th time slot generated by the EDD scheduler 120 will be The latest scheduling result of the K th time slot is output to the N current count value generators 110-1 to 110-n, and the current scheduling result of the K th time slot generated by the EDD scheduler 120 is used as the (K th time slot) +1) The latest scheduling result of the time slot is output to the N current count value generators 110-1 to 110-n. In addition, the parameter configuration of the packet transmission demander MGk can be based on the mode of the packet transmission demander MGk (for example: full line rate (line rate) mode or oversubscription (oversubscription; OS) mode), bandwidth requirements of the packet transmission demander, and A core bandwidth (eg, the core bandwidth of a network device including the TDM scheduler 100 ) is determined. For example, in the case that the core bandwidth is less than the sum of the bandwidth requirements of the N packet transmission requirements, the parameter configuration (especially the setting of the aforementioned counting range) of each packet transmission requirement, the parameter The configuration will give priority to meeting the bandwidth requirements of the demanders in the full wire-speed mode, and then serve part of the bandwidth requirements of the demanders in the over-subscription mode based on the principle of best effort.

See Figure 1. The EDD scheduler 120 is used for generating a current scheduling result according to the N current count values and a predetermined urgency judgment rule for determining the service order, and optionally further according to the N packet transmission requesters MG1~ The transmission demand status of at least a part of the MGn (for example: the status of the buffer storing the packets to be transmitted by the/these packet transmission demanders) and the mode of each packet transmission demander (for example: full line rate mode or oversubscribed mode) ) to generate the current schedule result. For example, an extreme value among the N current count values (for example: when the preset counting rule adopts the aforementioned down counting rule, the extreme value is the minimum value among the N current count values; The counting rule adopts the aforementioned incremental counting rule, and the extreme value is the maximum value among the N current counting values) associated with one of the N packet transmission requesters (hereinafter referred to as the first target requester), and the EDD scheduler 120 Selecting the first target demander as a top priority object according to the preset urgency judgment rule; however, when the EDD scheduler 120 finds that the first target demander has no priority service demand according to the preset urgency judgment rule, The EDD scheduler 120 may select one of the other packet transmission requesters (hereinafter referred to as the second target requester) as the highest priority object according to the preset urgency judgment rule. The current scheduler associated with the second target requester Values may be: (1) The extreme value among the N current count values. In this case, the order of the second target demander is lower than the order of the first target demander, but higher than the order of other packet transmission demanders (if any) that are also associated with the extreme value. The EDD scheduler 120 learns the order of the N packet transmission requesters according to a preset order. (2) One extreme value among the N current count values (for example: the next smallest value or the next largest value among the N current count values). In this case, the current count values associated with other packet transmission demanders other than the second target demander are not equal to (less than or greater than) the next extreme value, or the second target demander is also associated with a higher order than others The order of the packet transmission requester of the next extreme value.

FIG. 3 shows an embodiment of the EDD scheduler 120 of FIG. 1 . As shown in FIG. 3 , the EDD scheduler 120 includes a conversion circuit 122 and a determination circuit 124 . The conversion circuit 122 is used for converting the N current count values into N priority values according to a preset conversion rule. The determination circuit 124 is used for generating the current scheduling result according to the N priority values; in this embodiment, the determination circuit 124 determines the packet transmission associated with the extreme value (eg, the minimum value or the maximum value) among the N priority values The demander is the highest priority object.

（例如：儲存封包傳輸需求者MGk之待傳輸封包的緩衝器的狀態），以產生該N個優先值；該傳輸需求狀態為一第一狀態或一第二狀態，該第一狀態表示有至少一待傳送封包，該第二狀態表示沒有任何待傳送封包；處於該第二狀態的所有封包傳輸需求者無優先服務需求，因此，轉換電路122可選擇性地將這種封包傳輸需求者的當前計數值轉換為一最低優先值，該最低優先值可視實施需求而預設。另外，對於無優先服務需求且讓出傳輸機會的封包傳輸需求者MGk，轉換電路122可輸出一重載訊號RELOAD_MG，以通知計數電路114-k載入它的初始計數值

如前所述。 See Figure 3. In an implementation example, the conversion circuit 122 refers to the respective transmission demand states of the N packet transmission demanders according to the preset conversion rule

(For example: storing the state of the buffer of the packet to be transmitted by the packet transmission requester MGk) to generate the N priority values; the transmission request state is a first state or a second state, and the first state indicates that there are at least A packet to be transmitted, the second state indicates that there is no packet to be transmitted; all packet transmission requesters in the second state have no priority service requirements, therefore, the conversion circuit 122 can selectively transfer the current packet transmission requester's current The count value is converted into a lowest priority value, and the lowest priority value can be preset according to implementation requirements. In addition, for the packet transmission demander MGk that has no priority service demand and has given up the transmission opportunity, the conversion circuit 122 can output a reload signal RELOAD_MG to notify the counting circuit 114-k to load its initial count value

As mentioned earlier.

，以產生該N個優先值。該最小服務間隔狀態值指出它所關聯的一封包傳輸需求者是否已達到未被服務的一時間門檻；當該封包傳輸需求者持續未被服務的時間已達到該時間門檻時（亦即：當該最小服務間隔狀態值為一特定值如後所述），該封包傳輸需求者有資格作為該最優先對象；當該封包傳輸需求者持續未被服務的時間未達到該時間門檻，轉換電路122可選擇性地將該封包傳輸需求者的當前計數值轉換為該最低優先值。 See Figure 3. In an implementation example, the conversion circuit 122 refers to a minimum service interval status value of each of the N packet transmission requesters according to the preset conversion rule

, to generate the N priority values. The minimum service interval status value indicates whether a packet transmission demander associated with it has reached a time threshold of not being served; when the packet transmission demander has not been served for a period of time that has reached the time threshold (ie: when The minimum service interval status value is a specific value (as described later), the packet transmission requester is eligible to be the highest priority object; when the packet transmission requester has not been served for a period of time that does not reach the time threshold, the conversion circuit 122 Optionally, the current count value of the packet transmission requester can be converted into the lowest priority value.

See Figure 3. In an implementation example, for a packet transmission requester in full wire-speed mode that has not given up a transmission opportunity and has reached the time threshold, if its/their current count value is not the extreme value within its/their count range, The conversion circuit 122 converts its/their current count values to the lowest priority value according to the preset conversion rule, and otherwise treats its/their current count values as their priority values. In an implementation example, for the packet transmission demander in the oversubscription mode that has not given up the transmission opportunity and has reached the time threshold, the conversion circuit 122 regards its/their current count value as their current count value according to the preset conversion rule. priority value.

It is worth noting that the minimum service interval state value MGk_MIN_VLD can be generated by the aforementioned current count value generator 110-k; for example, the parameter configuration of the packet transmission demander MGk includes the minimum service interval value _MCNTk of the demander MGk (for example: positive integer); the current count value generator 110-k loads the minimum service interval value MCNT _k at the beginning of counting, and decrements the minimum service interval value MCNT _k every time at least one time slot passes ; When MCNT _k is not zero, the current count value generator 110-k generates a first value (eg: 0) according to the minimum service interval status value to indicate that the demander MGk cannot yet be the highest priority object; when MCNT When _k is zero, the current count value generator 110-k generates a second value (eg, 1) for the minimum service interval status value based on the current count value generator 110-k, indicating that the demander MGk can be the highest priority object.

FIG. 4 shows an application example of the TDM scheduler 100 of FIG. 1 . In this example, the TDM scheduler 100 is included in an Ethernet switch 400 , and the core bandwidth (or called core full line rate bandwidth) of the switch 400 is 400 Gbps. The TDM scheduler 100 is used for allocating time slots to six packet transmission requesters MG1~MG6 (for example, six Ethernet ports) to allow them to transmit packets in the allocated time slots, among which MG1~MG4 The input/output bandwidth (or demanded bandwidth) of each of them is 100Gbps, the input/output bandwidth of each of MG5~MG6 is 50Gbps, MG1~MG3 are in full line speed mode, and MG4~MG6 are in oversubscription mode. Based on the mode in which MG1~MG6 are in, the TDM scheduler 100 will allocate 100Gbps of switch core bandwidth to each of MG1~MG3, and allocate the remaining switch core bandwidth of 100Gbps to MG4~MG6 for common use.

（例如：數值3到數值0，其表示該封包傳輸需求者可使用總核心頻寬的

），計算/設定MG4所關聯的計數範圍為

（例如：數值8到數值1，其表示該封包傳輸需求者可使用總核心頻寬的

），以及設定MG5~MG6之每一個所關聯的計數範圍為

（例如：數值16到數值1，其表示該封包傳輸需求者可使用總核心頻寬的

）。值得注意的是，本領域具有通常知識者能夠依據本揭露利用已知或自行開發的電路來實現上述範圍的計算/設定。另值得注意的是，若計算出的計數範圍帶有小數時，TDM排程器100/該外部裝置可將該小數無條件捨去（chop）；然此並非本發明的實施限制。 See Figure 4. The TDM scheduler 100 can realize the above allocation through the aforementioned parameter configuration of each packet transmission requester. For example, the TDM scheduler 100 or an external device (not shown) can calculate/set the count range associated with each of MG1 to MG3 as

(For example: a value of 3 to a value of 0, which indicates that the packet transmission requester can use the total core bandwidth

), calculate/set the count range associated with MG4 to

(For example: a value of 8 to a value of 1, which indicates that the packet transmission requester can use the total core bandwidth

), and set the count range associated with each of MG5~MG6 as

(For example: a value of 16 to a value of 1, which indicates that the requester of the packet transmission can use a percentage of the total core bandwidth

). It is worth noting that those with ordinary knowledge in the art can use known or self-developed circuits to realize the calculation/setting of the above-mentioned range according to the present disclosure. It is also worth noting that if the calculated count range has a decimal, the TDM scheduler 100/the external device can unconditionally chop the decimal; however, this is not a limitation of the present invention.

FIG. 5 shows the time slot allocation result of the example of FIG. 4 , each time slot corresponds to a top priority object (eg, a selected transmission port) that can transmit packets in the time slot. As shown in FIG. 5 , the default order of MG1 to MG6 is MG1 > MG2 > MG3 > MG4 > MG5 > MG6, which is determined by a predetermined order, which indicates that the order of demanders in full line speed mode is higher than The order of demanders in the over-subscription mode, and the order of demanders with high bandwidth demand is higher than the order of demanders with low bandwidth demand; however, the arrangement of the preset order is not limited to the above method, and can be determined according to the implementation demand. Figure 5 shows: (1) The initial value of all demanders MG1~MG6 (ie: the aforementioned current count value) is the extreme value (here, the minimum value) within their associated count range. It is worth noting that the extreme value of demanders in the full line speed mode (0 in the example of Figure 4) is different from the extreme value of demanders in the oversubscribed mode (1 in the example of Figure 4) to ensure full line speed. The time slot allocation priority of the demander in the mode is higher than the time slot allocation priority of the demander in the over-subscription mode. (2) The TDM scheduler 100 (mainly the EDD scheduler 120 ) selects an extreme value (the minimum value here) from the six current count values MG1_DCNT_VAL~MG6_DCNT_VAL corresponding to the Kth time slot (K is a positive integer). , and regard the demander associated with the extreme value as a top priority object (for example: the demander MG1 associated with the minimum value 0 of the 0th time slot); if there are multiple count values in the six current count values For the same extreme value, the TDM scheduler 100 selects a highest-ranked one among the plurality of demanders as the highest-priority object according to the aforementioned predetermined order. (3) Following (2), after the top priority object is selected, the current count values of all the Kth time slots are regarded as the previous count values of the (K+1)th time slot, and the TDM scheduler 100 (mainly N The current count value generators 110-1 to 110-n) generate the current count value of the (K+1)th time slot according to the previous count values, wherein the TDM scheduler 100 performs the following operations: loading the Kth time slot The initial count value of the highest priority object (for example: the initial count value 3 of the highest priority object MG1 in the 0th time slot) is used as the current count value of its (K+1)th time slot; if an unselected demander The previous count value of the (K+1)th time slot is not the minimum value within the count range associated with the demander, and the previous count value of the (K+1)th time slot of the demander is subtracted by a preset value / The compensation value is as described above, so that the current count value of the (K+1)th time slot that generates it approaches the extreme value; if the previous count value of the (K+1)th time slot of an unselected demander The value is the minimum value in the count range associated with the demander, and the previous count value of the demander's (K+1)th time slot is regarded as the current count value of its (K+1)th time slot (also That is: keep the current count value of the demander unchanged); then the TDM scheduler 100 (mainly the EDD scheduler 120 ) selects an extreme value from the six current count values corresponding to the (K+1)th time slot (here is the minimum value), and the demander associated with this extreme value is regarded as a top priority object. (4) In the above points (2) to (3), the TDM scheduler 100 (mainly the EDD scheduler 120 ) may selectively refer to the transmission demand status of at least a part of MG1 to MG6. As described above, to determine the highest priority object. It is worth noting that, for a packet transmission requester that has no priority service requirement in the Kth time slot, if it is originally the highest priority object and is set to the full wire-speed mode, the TDM scheduler 100 will also load its initial schedule. The value is taken as the current count value of its (K+1)th time slot. It is also worth noting that, if the packet transmission demander in the full wire speed mode has no priority service demand, its transmission opportunity can be limited to only the packet transmission demander in the oversubscribed mode; however, this is not an implementation limitation of the present invention. (5) In the above points (2) to (3), the TDM scheduler 100 (mainly the EDD scheduler 120 ) may selectively refer to the minimum service interval status value of each of MG1 to MG6 as described above to determine the highest priority object.

It is worth noting that although the TDM scheduler 100 (mainly the N current count value generators 110-1 to 110-n) in the example of FIG. The case when the incremental counting rule is adopted can be deduced by analogy; therefore, repeated and redundant descriptions are omitted here.

FIG. 6 is an example showing how the aforementioned compensation value is used for a slot allocation result. In the example of FIG. 6 , both MG1 and MG2 are set in oversubscription mode, in which the count range of packet transmission demander MG1 is from 5 to 1, and the count range of packet transmission demander MG2 is from 10 to 1. Please refer to Fig. 6, in a first situation (for example: a situation where there are many demanders competing for time slots), MG1 gets a transmission opportunity every 5 time slots (that is, it is selected as the highest priority object), and MG2 gets a transmission opportunity every 5 time slots. 10 time slots get a transmission opportunity, and each of MG1 and MG2 gets a transmission opportunity when its current count value is the minimum value within its count range; MG1 gets a transmission opportunity every 4 time slots, MG2 gets a transmission opportunity every 8 time slots, at this time, MG1 is in its current count value not the minimum value within its count range Therefore, when MG1 obtains a transmission opportunity at the Kth time slot (for example, the 4th time slot in the second case of Figure 6), the current count value of MG2 at the (K+1)th time slot will be: The current count value of the Kth time slot of MG2 minus the preset value (here is 1), and then subtract the current count value of the Kth time slot of MG1 and the minimum value within the count range of MG1 (here is 1) ), the sum of the preset value and the difference is the compensation value.

FIG. 7 shows an embodiment of the TDMA scheduling apparatus of the present disclosure, which can determine a service order of N packet transmission demand groups MG1 ˜MGn. The embodiment of FIG. 7 is applicable to a situation where at least one of the N packet transmission demand groups MG1 ˜MGn includes a plurality of transmission ports. The TDM scheduler 700 of FIG. 7 can be used in a network device (eg, an Ethernet switch), and includes a TDM scheduler 710 (eg, the TDM scheduler 100 of FIG. 1 ) and a transmission port row The scheduler 720, wherein the TDM scheduler 710 is used to select one of the N packet transmission request groups MG1-MGn. As mentioned above, the transmission port scheduler 720 is used to determine the selected packet transmission request group. Which of the M transmission ports, the M is a positive integer.

用來服務一封包傳輸需求群組MGk，該封包傳輸需求群組MGk包含至少一傳輸埠。每個排程電路722-k用來依據複數個排程參數與一預設演算法（例如：已知的加權式輪詢（Weighted round robin; WRR）演算法，或自定義的加權式輪詢演算法），輸出一傳輸埠選擇訊號MGk_SEL_PORT指出封包傳輸需求群組MGk的一傳輸埠；因此，N個排程電路722-1~722-n共輸出了N個傳輸埠選擇訊號MG1_SEL_PORT~MGn_SEL_PORT指出N個傳輸埠。本實施例中，每個排程電路722-k所接收的排程參數包含：封包傳輸需求群組MGk之每個傳輸埠的傳輸需求狀態；封包傳輸需求群組MGk之每個傳輸埠的權值；指出封包傳輸需求群組MGk所處模式（亦即：全線速模式或超額認購模式）的參數，其可由TDM排程器710提供；以及第一多工器724與第二多工器726的輸出。另外，本實施例中，若封包傳輸需求群組MGk處於超額認購模式，排程電路722-k採用的預設演算法為已知的WRR演算法；若封包傳輸需求群組MGk處於全線速模式，排程電路722-k採用的預設演算法為一TDM WRR演算法。該TDM WRR演算法與該WRR演算法的區別在於TDM WRR演算法不考慮封包傳輸需求群組MGk的傳輸埠是否有封包待轉發。 See Figure 7. The transmission port scheduler 720 includes N scheduling circuits 722 - 1 to 722 - n , a first multiplexer 724 and a second multiplexer 726 . per scheduling circuit

It is used for serving a packet transmission requirement group MGk, and the packet transmission requirement group MGk includes at least one transmission port. Each scheduling circuit 722-k is used for a plurality of scheduling parameters and a predetermined algorithm (eg, a known weighted round robin (WRR) algorithm, or a custom weighted round robin) algorithm algorithm), outputs a transmission port selection signal MGk_SEL_PORT to indicate a transmission port of the packet transmission request group MGk; therefore, the N scheduling circuits 722-1~722-n output a total of N transmission port selection signals MG1_SEL_PORT~MGn_SEL_PORT to indicate N transmission ports. In this embodiment, the scheduling parameters received by each scheduling circuit 722-k include: the transmission demand status of each transmission port in the packet transmission demand group MGk; the weight of each transmission port in the packet transmission demand group MGk value; a parameter indicating the mode in which the packet transmission request group MGk is in (ie: full line rate mode or oversubscribed mode), which can be provided by the TDM scheduler 710; and the first multiplexer 724 and the second multiplexer 726 Output. In addition, in this embodiment, if the packet transmission demand group MGk is in the oversubscribed mode, the preset algorithm used by the scheduling circuit 722-k is the known WRR algorithm; if the packet transmission demand group MGk is in the full wire-rate mode , the preset algorithm used by the scheduling circuit 722-k is a TDM WRR algorithm. The difference between the TDM WRR algorithm and the WRR algorithm is that the TDM WRR algorithm does not consider whether the transmission port of the packet transmission requirement group MGk has packets to be forwarded.

See Figure 7. The first multiplexer 724 is used for outputting a selected transmission port signal SEL_PORT to indicate the N according to a highest priority object indicated by a demand group selection signal SEL_MG included in the current scheduling result output by the TDM scheduler 710 One of the transmission ports is used as a selected transmission port, thereby allowing the selected transmission port to transmit, wherein the highest priority object is one of the N packet transmission request groups, and the selected transmission port is the selected transmission port. One of the M ports of the highest priority object.

See Figure 7. The second multiplexer 726 is used for outputting a transmission port reloading signal RELOAD_PORT according to a reloading signal RELOAD_MG included in the current scheduling result output by the TDM scheduler 710 to indicate the Yth transmission among the N transmission ports port (the transmission port associated with the requester who gave up the transmission opportunity, if any), thereby informing the Y th scheduled circuit associated with the Y th transmission port among the N scheduled circuits according to the preset algorithm Decrease the transmission priority of the Y-th transmission port, where Y is a positive integer.

Since those with ordinary knowledge in the art can refer to the disclosure of the embodiments of FIGS. 1-6 and the known/self-developed algorithms to deduce the details and variations of the embodiment of FIG. 7 , repeated and redundant descriptions are omitted here. .

Please note that under the premise of possible implementation, those skilled in the art can selectively implement some or all of the technical features in any of the foregoing embodiments, or selectively implement some or all of the techniques in the foregoing multiple embodiments. A combination of features, thereby increasing the flexibility in the practice of the present invention.

To sum up, the present invention can automatically allocate time slots for a plurality of packet transmission demanders, which not only greatly saves manpower, but also can quickly realize the planning of time slot allocation.

Although the embodiments of the present invention are described above, these embodiments are not intended to limit the present invention. Those skilled in the art can change the technical features of the present invention according to the explicit or implicit contents of the present invention. All such changes may belong to the scope of patent protection sought by the present invention. In other words, the scope of patent protection of the present invention shall be determined by the scope of the patent application in this specification.

100: Time-sharing scheduler (TDM scheduler) MG1~MGn: N demanders of packet transmission 110-1~110-n: N current count value generators 120: Earliest Expiration Scheduler (EDD Scheduler) MG1_DCNT_VAL~MGn_DCNT_VAL: N current count values 110-k: Current count value generator 112-k: Storage circuit 114-k: Counting circuit MGk_DCNT_VAL: current count value 122: Conversion circuit 124: Decision Circuit MG1_PGAE_VLD~MGn_PGAE_VLD: Transmission demand status MG1_MIN_VLD~MGn_MIN_VLD: Minimum service interval status value RELOAD_MG: reload signal 400: Ethernet switch MG1~MG6: Packet transmission demander 700: Time-sharing multiplexing device (TDM scheduling device) 710: Time-sharing Multiplexing Scheduler (TDM Scheduler) 720: Port Scheduler 722-1~722-n: N scheduling circuits 724: First Multiplexer 726: Second Multiplexer MG1_SEL_PORT~MGn_SEL_PORT: Port selection signal SEL_MG: Demand group selection signal SEL_PORT: Selected transmission port signal RELOAD_PORT: port reload signal

[FIG. 1] shows an embodiment of the time-sharing multiplexing scheduler (TDM scheduler) of the present disclosure; [Fig. 2] shows an embodiment of each current count value generator of Fig. 1; [FIG. 3] shows an embodiment of the earliest expiration scheduler (EDD scheduler) of FIG. 1; [Fig. 4] shows an application example of the TDMA scheduler of Fig. 1; [Fig. 5] shows the time slot allocation result of the example in Fig. 4; [Fig. 6] shows how a compensation value is used for a slot allocation result; and [ FIG. 7 ] shows an embodiment of the TDMA scheduling device of the present disclosure.

100: Time-sharing scheduler (TDM scheduler)

MG1~MGn: N demanders of packet transmission

110-1~110-n: N current count value generators

120: Earliest Expiration Scheduler (EDD Scheduler)

MG1_DCNT_VAL~MGn_DCNT_VAL: N current count values

Claims (10)

A time-division multiplexing scheduler (TDM scheduler), capable of determining a service order of N packet transmission requirements, where N is an integer greater than one, and the N packet transmission requirements include a first A demander and a second demander, the time-sharing scheduler includes: N current count value generators are used to serve the N packet transmission requesters respectively, each of the N current count value generators is used to generate a count value, and the N current count value generators are used to generate N The current count value and contains: a first count value generating circuit, comprising: a first storage circuit for storing the first parameter configuration of the first demander; and a first counting circuit for updating a first previous count value according to a plurality of first input parameters and a preset counting rule to generate a first current count value of the N current count values, wherein the plurality of first count values An input parameter includes the first parameter configuration and the first previous count value, the first previous count value is derived from a most recent scheduling result, the first previous count value and the first current count value both fall within a first Within a counting range, the first counting range is determined by the first parameter configuration and includes a first extreme value; a second count value generating circuit, comprising: a second storage circuit for storing the second parameter configuration of the second demander; and a second counting circuit for updating a second previous count value according to a plurality of second input parameters and the preset counting rule to generate a second current count value of the N current count values, wherein the plurality of first count values The two input parameters include the second parameter configuration and the second previous count value, the second previous count value is derived from the most recent scheduling result, and the second previous count value and the second current count value both fall within a first Within two count ranges, the second count range is determined by the second parameter configuration and includes a second extreme value; and an earliest due date (EDD) scheduler for generating a current scheduling result according to the N current count values and a predetermined urgency judgment rule, wherein the current scheduling result determines the service order, The most recent schedule result was previously generated by the earliest due scheduler. The time-sharing scheduler as claimed in item 1, wherein the first extreme value is a minimum value or a maximum value of the first count range; the second extreme value is a minimum value or a maximum value of the second count range. a maximum value; the first extreme value is equal to the second extreme value; when the first current count value is an extreme value among the N current count values and the second current count value is not equal to the extreme value or equal to At the second extreme value, the earliest expiry scheduler selects the first demander as a top priority object according to the preset urgency judgment rule; the extreme value is a minimum value among the N current count values or a maximum value. The time-sharing scheduler as claimed in item 1, wherein the first extreme value is a minimum value or a maximum value of the first count range; the second extreme value is a minimum value or a maximum value of the second count range. a maximum value; the first extreme value is equal to the second extreme value; when both the first current count value and the second current count value are an extreme value among the N current count values, the earliest The programmer selects the first demander as a top priority object according to the preset urgency judgment rule and a preset order of the N packet transmission demanders, and the extreme value is a minimum value among the N current count values or a maximum value, the preset order indicates that the first demander has a higher priority than the second demander. The time-sharing scheduler of request item 1, wherein the transmission mode of the first demander is a line rate mode, and the transmission mode of the second demander is an oversubscription mode; the The time division multiplexing scheduler is used in a switch; when the bandwidth demand of the first demander is not less than the bandwidth demand of the second demander and the total bandwidth demand of the N packet transmission demanders is greater than the switch When the core bandwidth is 100%, the first count range is smaller than the second count range. The time-sharing scheduler of request item 1, wherein the transmission mode of the first demander is a full wire-speed mode, and the transmission mode of the second demander is an oversubscription mode; when the default counting rule adopts a In the down counting method, the first extreme value is smaller than the second extreme value; when the preset counting rule adopts an up counting method, the first extreme value is greater than the second extreme value. The time-sharing scheduler of request item 1, wherein an extreme value of the N current count values is associated with one of the N packet transmission requesters, and the extreme value of the N current count values A minimum value or a maximum value, and the earliest expiry scheduler selects the packet transmission requester associated with the extreme value as a top priority object according to the predetermined urgency judgment rule. The TDMA scheduler of request item 1, wherein the earliest due scheduler further generates the current scheduling result according to a transmission demand status of each of at least a portion of the N packet transmission demanders; the transmission The demand state is a first state or a second state, the first state indicates that there is at least one packet to be transmitted, and the second state indicates that there is no packet to be transmitted. A time-sharing multiplexing scheduler capable of determining a service order of N packet transmission requesters, where N is an integer greater than one, and the time-sharing multiplexing scheduler includes: N current count value generators are respectively used to serve the N packet transmission demand groups, and the N current count value generators are based on the parameters of the N packet transmission demand groups, a latest scheduling result and a preset The counting rule generates N current count values; an earliest expiration scheduler for generating a current scheduling result according to the N current count values and a predetermined urgency judgment rule, wherein the current scheduling result determines the service order, and the latest scheduling result is the Earliest expiry scheduler previously generated. The time-sharing scheduler of claim 8, wherein the earliest expiry scheduler comprises: a conversion circuit for converting the N current count values into N priority values according to a predetermined conversion rule; and a decision circuit for generating the current scheduling result according to the N priority values, wherein the decision circuit selects a packet transmission requester associated with an extreme value of the N priority values as a highest priority object, and the highest priority The priority object is the one with the highest order in the service order. A time-sharing multiplexing scheduling device, the time-sharing multiplexing scheduling device comprises: One-time multiplexing scheduler, including: N current count value generators are respectively used to serve N packet transmission request groups, and the N current count value generators are based on the parameters of the N packet transmission request groups, a latest scheduling result and a preset count The rule produces N current count values; and an earliest expiration scheduler for generating a current scheduling result according to the N current count values and a predetermined urgency judgment rule, and the latest scheduling result was previously generated by the earliest expiration scheduler; and A port scheduler, including: N scheduling circuits are respectively used to serve the N packet transmission request groups, each of the N packet transmission request groups includes at least one transmission port, and each scheduling circuit is used for selecting according to a predetermined algorithm A transmission port of the packet transmission request group served by the scheduling circuit, the N scheduling circuits selecting N transmission ports; and a multiplexer for outputting a transmission port selection signal according to a highest priority object indicated by the current scheduling result to indicate one of the N transmission ports as a selected transmission port, thereby allowing the selected transmission port For transmission, the highest priority object is one of the N packet transmission request groups, the selected transmission port is one of M transmissions of the highest priority object, and M is a positive integer.

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